# Bardet-Biedl vs Laurence-Moon: The Obesity Clue **By Paula Gallagher** · 2026-08-18 ![Photograph illustrating Bardet-Biedl Syndrome and genetic obesity symptoms — genetic obesity syndrome, food noise](https://cdn.shopify.com/s/files/1/0319/0960/9603/files/thumb-fix-675052945646.png?v=1787068342&width=300&height=200&crop=center) **Bardet-Biedl** **syndrome and Laurence-Moon syndrome** share a name and a genetic root, but they are not the same thing. Bardet-Biedl syndrome is an autosomal recessive ciliopathy that classically brings early-onset obesity, extra fingers or toes, and progressive vision loss. Laurence-Moon was historically grouped with it, but that older label leaned more on spastic paraplegia and less on polydactyly and obesity. The two overlap so much that the combined term "Laurence-Moon-Bardet-Biedl" persisted for decades. Today most clinicians help with them as distinct. Here's what actually separates them, and why the relentless hunger seen in Bardet-Biedl is a signaling problem, not a willpower one. ## Two Syndromes, One Confusing Name It’s why you’ll often see them referred to with one hyphenated term: Bardet-Biedl syndrome. That’s why you’ll often see a search result that reads “Bardet-Biedl syndrome vs Laurence Moon Bardet Biedl.” Short answer: They're both ciliopathies that cause retinal degeneration. In Laurence-Moon, neurological signs such as spastic paraplegia predominate; there's usually less obesity, and no extra digits. Bardet-Biedl, however, involves polydactyly, obesity that starts in childhood, kidney complications, and hormone imbalances. Today, most modern genetic testing will help distinguish them as different conditions with some overlap in symptoms. ## The Genetic Mutation Behind the Cilia The Bardet-Biedl syndrome genetic cause traces back to primary cilia. They are small, hair-like extensions of the cell surface. But cilia also do the work of the cell. They act as anchors, messengers, and transport systems, carrying receptors and vesicles around the cell. The failure of transport through mutations in the genes responsible for building and maintaining cilia occurs simultaneously throughout various organs. This is the reason why a single disease can affect multiple organs like the eyes, kidneys, brain, and reproductive organs. BBS is associated with over 20 genes. It is inherited in an autosomal recessive manner, which means that children inherit one copy of the mutation from each parent. - The most frequently reported variants are in BBS1 and BBS10. - Cilia dysfunction also impacts sperm motility, hence the prevalence of infertility problems. - This same broken signaling affects the brain's control of appetite. ## How Bardet-Biedl Syndrome Drives Obesity ![How Bardet-Biedl Syndrome Drives Obesity](https://cdn.shopify.com/s/files/1/0319/0960/9603/files/asset-1786977459831.png?v=1786980493) BBS obesity begins in childhood, and it is caused by unrelenting hunger that the brain cannot turn off. People describe this as "food noise," a term that describes the constant urge to eat. It may also be called hyperphagia. Not your typical cravings, these are a message from your body that something has gone wrong with the signals between your brain and your gut. Usually, leptin from your fat cells signals to the brain that there is sufficient energy stored. In BBS that leptin pathway is broken, so the "you're full" message never lands. This is why BBS is so often misdiagnosed as a lack of willpower. The person is fighting a biological issue, not a lack of discipline. ## The Eye Symptoms You Notice First ![The Eye Symptoms You Notice First](https://cdn.shopify.com/s/files/1/0319/0960/9603/files/asset-1786977762631.png?v=1786980497) For some families, it's the Bardet-Biedl syndrome eye symptoms that provide the first true clue. The retina begins its slow degeneration. The disease typically starts out as night blindness and constricted peripheral vision, and then worsens until patients become legally blind. As the retina is rich in cilia-bearing cells, this symptom is seen early on and is very common for BBS. Nutrition can't improve a genetic retinal condition, but some people ask us about general eye-health support as part of a broader wellness routine. Nutrients like lutein, bilberry, and omega-3s have been studied for eye health, and options such as [**ProDHA Eye**](https://myvillanegreen.com/products/prodha-eye "https://myvillanegreen.com/products/prodha-eye") or [**Bilberry Extract Plus**](https://myvillanegreen.com/products/bilberry-extract-plus "https://myvillanegreen.com/products/bilberry-extract-plus") may help support the eyes as part of daily care. You can browse our full **[Eye Health](https://www.myvillanegreen.com/collections/eye-health "https://www.myvillanegreen.com/collections/eye-health")** collection to see what fits. ## Telling It Apart From Alstrom Syndrome Bardet-Biedl syndrome vs Alstrom syndrome? They are both ciliopathies that share the features of obesity and vision loss. What sets these syndromes apart is the hands and feet. While Alstrom syndrome doesn't include polydactyly, extra digits are one of the hallmarks of BBS. Alstrom also brings hearing loss and heart muscle issues earlier and more visibly. A lifelong weak or absent sense of smell, anosmia or hyposmia, is a minor diagnostic criterion for BBS, and an easy screening question that a doctor could ask. To separate them out you need clinical and genetic assessments, rather than a single symptom. As the original post put it: "One of the minor diagnostic criteria for Bardet-Biedl Syndrome is lifelong anosmia or hyposmia, meaning you have a weak or missing sense of smell your entire life, which is a quick and overlooked screening question any doctor can ask." ## Inheritance, Testing, and Who helps with the Weight ![Inheritance, Testing, and Who helps with the Weight](https://cdn.shopify.com/s/files/1/0319/0960/9603/files/asset-1786978078848.png?v=1786980501) BBS is inherited in an autosomal recessive fashion, meaning that both parents are typically unaffected carriers of BBS. That’s why there are usually no Bardet-Biedl syndrome carrier symptoms present in either parent. Bardet-Biedl syndrome genetic testing is used to confirm the diagnosis of Bardet-Biedl syndrome by revealing the specific Bardet-Biedl syndrome genetic mutation. Commercial panels are just one way to look for genetic causes, but the diagnosis itself continues to be based on major and minor criteria in addition to the genetics. A key drug in the Bardet-Biedl syndrome obesity treatment space is setmelanotide. It functions by circumventing broken leptin signaling to signal the brain that there’s enough fat stored. Other options in metabolic care include GLP-1 medications and bariatric surgery. Both of these are prescriptions made with a specialist. If severe hunger has been dismissed as willpower and your labs deserve a closer look, our team can help you review them and coordinate with your physician. You can **[book a lab review consultation](https://www.myvillanegreen.com/pages/appointment-for-your-lab-review-consultation "https://www.myvillanegreen.com/pages/appointment-for-your-lab-review-consultation")** to talk it through. ## Key Takeaways - Bardet-Biedl syndrome results from defective primary cilia, the tiny cellular projections that ferry receptors and signals between cells. - It is characterized by early-onset obesity, retinal dystrophy frequently resulting in legal blindness, and postaxial polydactyly. - The insatiable hunger, also known as “food noise” or “hyperphagia,” reflects broken brain-body signaling, not a failure of willpower. - The medication, setmelanotide, bypasses broken leptin signaling and has already led to larger weight loss among BBS patients compared with people with conventional obesity. - A lifelong weak or absent sense of smell is a minor criterion and an easy screening question. ## Frequently Asked Questions ### How does Bardet-Biedl syndrome cause obesity BBS damages the primary cilia in brain regions that regulate appetite, so the leptin signal that normally says "you have enough fat stored" never registers. The result is hyperphagia, or relentless hunger, that begins in early childhood. It's a broken signaling loop, not a behavior problem. That's why targeted treatments like setmelanotide, which bypass the broken pathway, can work when general weight strategies stall. ### What is Bardet-Biedl syndrome symptoms   The most well-known symptoms include early onset obesity, retinal dystrophy which may lead to blindness, and having extra fingers or toes (polydactyly). There can also be kidney problems, hormonal and reproductive issues, and learning differences. Other minor symptoms include a lifelong poor or absent sense of smell, dental changes, and fatty liver. Every person’s experience is unique. ### Who discovered Bardet-Biedl syndrome Bardet-Biedl syndrome was named for Georges Bardet and Arthur Biedl, the doctors who reported the clinical features of the disorder in the first half of the 20th century. John Laurence and Robert Moon had reported a similar syndrome earlier, Laurence-Moon syndrome. For a long time, the syndromes were lumped together as Laurence-Moon-Bardet-Biedl syndrome until geneticists determined that they were actually different disorders. ### How is Bardet-Biedl syndrome inherited This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. Most often, the parents of an individual with an autosomal recessive condition are carriers of one copy of the mutated gene but do not show signs and symptoms of the condition. More than 20 BBS genes have been identified. ### How is Bardet-Biedl syndrome diagnosed Diagnosis is based on meeting a certain number of major criteria (retinal dystrophy, polydactyly, obesity, renal problems, learning difficulties) and minor criteria (hyposmia). Testing is also performed using genetic panels to identify specific mutations. Screening tools such as the GOSS scale can be used to determine who needs further evaluation. ### How common is Bardet-Biedl syndrome Bardet-Biedl syndrome is rare and prevalence estimates vary according to population; it may be more common in certain populations that have greater levels of shared ancestry. Since the signs and symptoms can overlap with other conditions and may develop over time, it is likely that many cases of Bardet-Biedl syndrome go undiagnosed. Patient registries help researchers learn more about this condition by tracking cases and identifying additional people with the condition as they develop. **Tags:** bardet biedl syndrome and obesity, bardet biedl syndrome carrier symptoms, bardet biedl syndrome genetic cause, bardet biedl syndrome genetic mutation, bardet biedl syndrome obesity, bardet biedl syndrome vs laurence moon bardet biedl --- > Source: [Village Green Apothecary](https://myvillanegreen.com/blogs/post/bardet-biedl-vs-laurence-moon-bardet-biedl)